Chapter 9. introduction to network management. major components. MIB: management information base. SNMP: protocol for network management

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1 Chapter 9 Network Management A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: If you use these slides (e.g., in a class) in substantially unaltered form, that you mention their source (after all, we d like people to use our book!) If you post any slides in substantially unaltered form on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. Thanks and enjoy! JFK/KWR All material copyright J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach, 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, sl July Network Management 9-1 Chapter 9: Network Management Chapter goals: introduction to network management motivation major components Internet network management framework MIB: management information base SMI: definition language SNMP: protocol for network management security and administration presentation services: ASN.1 Network Management 9-2 Chapter 9 outline What is network management? What is network management? Internet-standard management framework Structure of Management Information: SMI Management Information Base: MIB SNMP Protocol Operations and Transport Mappings Security and Administration ASN.1 Network Management 9-3 autonomous systems (aka network ): 100s or 1000s of interacting hardware/software components other complex systems st s requiring i monitoring, i control: jet airplane nuclear power plant others? "Network management includes the deployment, integration and coordination of the hardware, software, and human elements to monitor, test, poll, configure, analyze, evaluate, and control the network and element resources to meet the real-time, operational performance, and Quality of Service requirements at a reasonable cost." Network Management 9-4

2 Infrastructure for network management definitions: managing entity managing entity network management protocol agent agent s contain managed objects whose is gathered into a agent Management Information Base (MIB) agent Network Management standards OSI CMIP SNMP: Simple Network Common Management Management Protocol Information Protocol Internet t roots (SGMP) designed 1980 s: the started simple unifying net deployed, d adopted d rapidly management standard growth: size, complexity too slowly currently: SNMP V3 standardized de facto network management m nt standard d Network Management 9-5 Network Management 9-6 Chapter 9 outline What is network management? Internet-standard management framework Structure of Management Information: SMI Management Information Base: MIB SNMP Protocol Operations and Transport Mappings Security and Administration ASN.1 SNMP overview: 4 key parts Management information i base (MIB): distributed information store of network management Structure of Management Information (SMI): definition language for MIB objects SNMP protocol convey manager<->managed object info, commands security, administration capabilities major addition in SNMPv3 Network Management 9-7 Network Management 9-8

3 SMI: definition language SNMP MIB Purpose: syntax, semantics of management welldefined, unambiguous base types: straightforward, boring OBJECT-TYPE type, status, semantics of managed object MODULE-IDENTITY groups related objects into MIB module Basic Data Types INTEGER Integer32 Unsigned32 OCTET STRING OBJECT IDENTIFIED IPaddress Counter32 Counter64 Guage32 Time Ticks Opaque Network Management 9-9 MIB module specified via SMI MODULE-IDENTITY (100 standardized MIBs, more vendor-specific) MODULE OBJECT TYPE: OBJECT TYPE: OBJECT TYPE: objects specified via SMI OBJECT-TYPE construct Network Management 9-10 SMI: Object, module examples MIB example: UDP module OBJECT-TYPE: TYPE ipindelivers ipindelivers OBJECT TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION The total number of input grams successfully delivered to IP user- protocols (including ICMP) ::= { ip 9} MODULE-IDENTITY: ipmib ipmib MODULE-IDENTITY LAST-UPDATED Z ORGANZATION IETF SNPv2 Working Group CONTACT-INFO Keith McCloghrie DESCRIPTION The MIB module for managing IP and ICMP implementations, but excluding their management of IP routes. REVISION Z ::= {mib-2 48} Network Management 9-11 Object ID Name Type Comments UDPInDatagrams Counter32 total # grams delivered at this node UDPNoPorts Counter32 # underliverable grams no app at portl UDInErrors Counter32 # undeliverable grams all other reasons UDPOutDatagrams Counter32 # grams sent udptable SEQUENCE one entry for each port in use by app, gives port # and IP address Network Management 9-12

4 SNMP Naming question: how to name every possible standard object (protocol,, more..) in every possible network standard?? answer: ISO Object Identifier tree: hierarchical naming of all objects each branchpoint has name, number OSI Object Identifier Tree ISO ISO-ident. Org. US DoD Internet udpindatagrams UDP MIB2 management Network Management 9-13 Check out Network Management 9-14 SNMP protocol Two ways to convey MIB info, commands: managing entity managing entity SNMP protocol: message types Message type Function GetRequest Mgr-to-agent: get me GetNextRequest (instance,next next in list, block) GetBulkRequest request response trap msg InformRequest Mgr-to-Mgr: Mgr: here s MIB value SetRequest Mgr-to-agent: g set MIB value agent Managed device request/response mode agent Managed device trap mode Response Trap Agent-to-mgr: value, response to Request Agent-to-mgr: inform manager of exceptional event Network Management 9-15 Network Management 9-16

5 SNMP protocol: message formats SNMP security and administration encryption: DES-encrypt SNMP message authentication: compute, send MIC(m,k): compute hash (MIC) over message (m), secret shared key (k) protection against playback: use nonce view-based access control SNMP entity maintains base of access rights, policies for various users base itself accessible as managed object! Network Management 9-17 Network Management 9-18 Chapter 9 outline What is network management? Internet-standard management framework Structure of Management Information: SMI Management Information Base: MIB SNMP Protocol Operations and Transport Mappings Security and Administration The presentation n problem: ASN.1 The presentation problem Q: does perfect memory-to-memory copy solve the communication problem? A: not always! struct { char code; int x; }test; test.x = 256; test.code= a test.code test.x a host 1 format test.code test.x a host 2 format problem: different format, storage conventions Network Management 9-19 Network Management 9-20

6 A real-life life presentation problem: Presentation problem: potential solutions grandma aging g 60 s hippie 2007 teenager 1. Sender learns receiver s format. Sender translates into receiver s format. Sender sends. real-world analogy? pros and cons?? 2. Sender sends. Receiver learns sender s format. Receiver translate into receiver-local format real-world-analogy pros and cons? 3. Sender translates host-independent format. Sends. Receiver translates to receiver-local format. real-world analogy? pros and cons? Network Management 9-21 Network Management 9-22 Solving the presentation problem 1. Translate local-host format to host-independent format 2. Transmit in host-independent format 3. Translate host-independent format to remote-host format grandma aging 60 s hippie 2007 teenager Network Management 9-23 ASN.1: Abstract Syntax Notation 1 ISO standard X.680 used extensively in Internet like eating vegetables, knowing this good for you! defined types, object constructors like SMI BER: Basic Encoding Rules specify how ASN.1-defined objects to be transmitted each transmitted object has Type, Length, Value (TLV) encoding Network Management 9-24

7 TLV Encoding Idea: transmitted is self-identifying T: type, one of ASN.1-defined types L: length of in bytes V: value of, encoded according to ASN.1 standard Tag Value Type 1 Boolean 2 Integer 3 Bitstring 4 Octet string 5 Null 6 Object Identifier 9 Real TLV encoding: example Value, 259 Length, 2 bytes Type=2, integer Value, 5 octets (chars) Length, 5 bytes Type=4, octet string Network Management 9-25 Network Management 9-26 Network Management: summary network managementm nt extremely important: 80% of network cost ASN.1 for description SNMP protocol as a tool for conveying information Network management: more art than science what to measure/monitor how to respond to failures? alarm correlation/filtering? Network Management 9-27